1967 911S engine wiring

[Terry Hohnecker]

This car experienced a small engine bay fire under the fuel pump awhile ago. It was rewired but the alternator is not charging the battery. The engine starts and runs fine. All gauges and lights work. The alternator has been checked twice by a major alternator/starter rebuild shop with both times telling me the alternator works fine. The regulator has also been okay by the shop. I feel something in the wiring is not correct. I've tried to follow a wiring diagram but with no luck. Is there anyone who could please send some pictures of their engine bay wiring or that I could possibly speak to?

[edmayo]

A fire and a rewire could have lots of possibilities, what does the shop that did the work say?

[Terry Hohnecker]

A fire and a rewire could have lots of possibilities, what does the shop that did the work say?

The alternator/starter rebuild shop said both the alternator and voltage regulator are working fine. Both were off the car and taken to J&N alternator/starters. The fire was very small in the fuel pump/coil area in the engine bay. It basically just melted the insulation from a few wires which I replaced with wire of the same color. The car starts and runs fine it's just not charging the battery. I'm thinking that wires are crossed or not hooked up at the wrong location. What would be handy would be a picture of the stock wiring of the electrical panel in the engine bay. Thanks for any help.

[edmayo]

Here is a picture of mine. There is a red/whi 6mm wire from the alternator that connects to the phenolic connection point at the lower left side of the relay board. A 6mm black wire also connects at that same terminal and goes to the starter solenoid where it joins with large battery cable, and from there goes forward to the battery. If those connections aren't made,,,,no battery charge. Also there must be a ground strap from the back of the alternator to the engine case. Did you install that when you reinstalled the alternator?

[Terry Hohnecker]

Thanks for the picture Ed, it was helpful to see a well organized relay board. I have a question about the wiring on the starter. Would you know by chance which cable goes on which post on the starter. I had the heavy cable on the left post in the picture and the thinner cable on the right post. Also could you take some additional pictures of the relay board from different angles so I could see better where the wires connect.

[edmayo]

Both the cables have to go on the same post, in your picture it would be the left post. In this way the alternator is connected to the battery. That picture was done before engine install, not as easy to get pictures now, what in particular are you trying to see?

[Terry Hohnecker]

Reconnected the starter cables correctly. Thanks for that info. Though that surely would fix the problem but still the red light is on. Tested the voltage regulator with both the ignition on and the motor running. No juice going to any connections of the v/r (D+ DF D-) any thoughts? There also is a ground cable going from the alternator case bolt to the engine case. Any pictures of the relay and resistor wiring would be helpful. Once I know that the wiring is correct and still no charge I will have the alternator checked by different shop.

[Richy]

If you were running the engine without the alternator connected to the battery , some diodes in your alternator are toast . The alternator light will stay on after the wire is connected . Have the alternator checked .

[edmayo]

Reconnected the starter cables correctly. Thanks for that info. Though that surely would fix the problem but still the red light is on. Tested the voltage regulator with both the ignition on and the motor running. No juice going to any connections of the v/r (D+ DF D-) any thoughts? There also is a ground cable going from the alternator case bolt to the engine case. Any pictures of the relay and resistor wiring would be helpful. Once I know that the wiring is correct and still no charge I will have the alternator checked by different shop.

Here are some pictures of my relay board. Of particular importance to you is the blue wire from the V.R. plug, notice that it is connected with a blue wire from the alternator charge bulb on your combo gauge. Without that in the circuit your alternator won't charge. Some of my wiring will look different from yours since I'm running a Bosch C.D.

[Terry Hohnecker]

Finally got the alternator done with the new diodes installed. Connected the cables to the right terminals on the starter per your information. Started the old girl up and voilà the light went off. Can not thank you enough! Been fighting this problem for quite awhile.Thanks again for the pics and advice.
TH